摘要 |
2-Oxo-1,2-dihydro-1,8-naphthyridine derivatives characterized by bearing a specific substituent, -X-R<6>, at the 3-position and a cyclic substituent, R<5>, at the 4-position; or salts thereof. The derivatives and the salts are useful as drugs, particularly preventive or therapeutic agents for respiratory diseases related to PDE IV. |